The effect of temperature and menthol on carbonation bite.

Temperature and chemesthesis interact, but this interaction has not been fully examined for most irritants. The current experiments focus on oral pungency from carbonation. Previous work showed that cooling carbon dioxide (CO2) solutions to below tongue temperature enhanced rated bite. However, to the best of our knowledge, the effects of warming to above tongue temperature have not been examined. In Experiment 1, subjects sampled CO2 solutions at 4 nominal concentrations (0.0, 2.0, 2.8, and 4.0 v/v) × 5 temperatures (18.3, 24.5, 29.9, 34.5, and 39.6 (o)C). Subjects dipped their tongue tips into samples and rated bite. As in previous work, subjects rated cool solutions (25.0 (o)C and lower) as more intense. Warming solutions above tongue temperature (39.6 (o)C) did not affect ratings. Experiment 2 examined warmer temperatures (18.3, 33.9, 39.0, 44.9, and 48.2 ºC). Bite was enhanced only at 48.2 ºC, and a follow-up experiment suggested that enhancement was probably due to confusion between carbonation bite and mild heat pain. Experiment 3 examined the effect of menthol cooling by pretreating the tongue with menthol. Unlike physical cooling, menthol cooling had little or no effect on rated bite. The results are discussed in the context of candidate transduction mechanisms for carbonation sensation.